The invention relates to a multi-cylinder stationary internal combustion engine—in particular a gas otto engine—with at least one throttle valve and with at least one compressor—in particular turbo-supercharger—for driving at least one generator for the production of electric current or for driving another consumer of mechanical energy.
Internal combustion engines according to the preamble are used both for the supply of individual local power consumers in so-called isolated operation and for the supply of power into the public system. The speed of the internal combustion engines is stabilized via an output regulator as long as the generator which is driven by the internal combustion engine is connected to the public system. If the generator is separated from the public system or if in isolated operation major power consumers are suddenly cut off, there is a sudden drop in load at the generator. The same applies to the uncoupling of the internal combustion engine from the generator or other sudden changes in operating conditions. In order to prevent an acceleration of the speed of the internal combustion engine, and thus negative effects on, or the destruction of, the latter in the event of such a drop in load, the throttle valve is completely closed for a brief period in the state of the art. As a consequence, because the compressor or turbo-supercharger is still operating at a high output level, so-called compressor or turbo-supercharger pumping occurs if the compressor is throttled in a working point with lots of throughput on the output side. This in turn leads to the danger of explosions in the exhaust pipe. This process of turbo-supercharger pumping—once started—is completely uncontrollable and leads in most cases to the complete loss of the supercharging pressure followed by the stopping of the internal combustion engine.
In order to improve the reaction to removal of the load in internal combustion engines, in particular gas otto engines, and prevent so-called compressor or turbo-supercharger pumping, it is already known to fit a blow-off valve downstream of the compressor in order to be able to reduce the supercharging pressure without turbo-supercharger pumping in the event of a brief shedding of load. However, these procedures known in the state of the art have the disadvantage that they require additional components such as e.g. blow-off valves and the regulator needed for these. Furthermore, a combustible fuel/air mixture is released by the blow-off valve, which in turn creates the need for safe handling of the blown-off fuel/air mixture and thus an additional outlay.